Electrical switch with cantilever spring retaining means for prevention of axial shaft movement

ABSTRACT

A shaft member in an electrical switch assembly is bodily shiftable between active and inactive positions to control the switch in one mode and carries a cantilever spring thereon having detent means which cantilever spring is self-biased toward an extended position wherein the detent means engage an abutment to significantly impede bodily shiftable movement of the shaft member from the active position thereof. The cantilever spring further includes a distal end spaced from the shaft member in the extended position of the cantilever spring which distal end is manually operable to displace the cantilever spring from the extended position to allow unimpeded bodily shiftable movement of the shaft member from the active to the inactive position.

United States Patent Inventor Richard M. Wagner Bloomfield Hills, Mich.

Appl. No. 879,103

Filed Nov. 24, I969 Patented June 8, 1971 Auignee General Motors Corporation Detroit, Mich.

ELECTRICAL SWITCH WITH CANTILEVER SPRING RETAINING MEANS FOR PREVENTION OF AXIAL SHAFT MOVEMENT 3 Claims, 4 Drawing Figs.

U.S. Cl 200/16, 209/166 Int. Cl. ll0lh 15/00, l-IOlh 3/00, l-IOlh 9/00 Field of Search 200/ l 6, 166

SD, 4, I61, 5 A; 74/527, 104

[56] References Cited UNITED STATES PATENTS 1,814,242 7/1931 Chryst et al ZOO/16X 3,228,254 1/1966 Biesecker 74/527X Primary Examiner-J. R. Scott Attorneys-W. E. Finken and D. L. Ellis ABSTRACT: A shaft member in an electrical switch assembly is bodily shiftable between active and inactive positions to control the switch in one mode and carries a cantilever spring thereon having detent means which cantilever spring is selfbiased toward an extended position wherein the detent means engage an abutment to significantly impede bodily shiftable movement of the shaft member from the active position thereof. The cantilever spring further includes a distal end spaced from the shaft member in the extended position of the cantilever spring which distal end is manually operable to displace the cantilever spring from the extended position to allow unimpeded bodily shiftable movement of the shaft member from the active to the inactive position.

ELECTRICAL SWITCH WITH CANTILEVER SPRING RETAINING MEANS FOR PREVENTION OF AXIAL SHAFT MOVEMENT This invention relates generally to electrical switch assemblies and in particular to automotive type headlamp switches.

In the design of automotive type instrument panels, one factor influencing the placement of the various controls thereon is the desire to minimize the possibility of inadvertent deactivation of the control while the vehicle is in operation. More particularly, the vehicle headlamp switch is typically situated in a somewhat remote portion of the instrument panel so that no portion of the operator's body is likely to contact the control unless such contact is consciously desired. As a means of further protection, the switch assembly according to this invention provides a detenting arrangement which maintains a switch shaft member in an active position and requires either the application of an unusually large effort or a positive detent releasing movement on the part of the operator before the switch can be deactivated. In either case, normal deactivation of the switch requires a conscious effort on the part of the operator in addition to bringing a part of his body into the area of the switch.

A primary feature, then, of this invention is that it provides an improved electrical switch assembly. Another feature of this invention is that it provides an improved electrical switch assembly wherein a shaft member is movable in a housing member between active and inactive positions and carries a cantilever spring self-biased toward an extended position wherein detent means on the cantilever spring engage abutment means to substantially impede movement of the shaft member from the active position. Yet another feature of this invention resides in the provision of abutment means in the form of a generally cylindrical collar member slidably receiving the shaft member and cantilever spring and engageable by the detent means on the latter to substantially impede movement of the shaft member from the active position thereof. Still another feature of this invention resides in the provision of selectively operable release means manually operable to displace the cantilever spring from the extended position so that movement of the shaft memberfrom the active to the inactive position is unimpeded. Yet another feature of the invention is that it provides detent means which are cammable under a force of sufficient magnitude to normally require conscious effort, but not so large as to present a solid projecting surface hazard in the vehicle. These and other features of this invention will be readily apparent from the following specifi cation and from the drawings wherein:

FIG. I is a partially broken away elevational view of an electrical switch assembly according to this invention and showing the shaft member in inactive position and the cantilever spring in retracted position;

FIG. 2 is similar to FIG. 1 but showing the showing the shaft member in active position and the cantilever spring in extended position;

FIG. 3 is a view ofa portion of FIG. I and showing the shaft member in active position and the cantilever spring in retracted position; and

FIG. 4 is an enlarged perspective view partially broken away and showing the shaft member, the cantilever spring, and the collar member.

Referring now to FIG. I of the drawings, an automobile type vehicle typically includes an instrument panel mounted by conventional means with a control mounting portion thereof in a generally vertical orientation in the vehicle interior. The instrument panel typically supports a plurality of controls required to regulate specific vehicular functions and, more particularly, supports an electrical switch assembly generally designated 12 adapted in a preferred embodiment to control the exterior vehicle illumination as well as instrument panel illumination.

The switch assembly 12 includes a housing member 14 having a hollow body portion 16 and an integral neck portion 18.

The neck portion 18 ofhousing member 14 includes an internally threaded counterbore 20 and a central circular bore 22 extending between the counterbore 20 and the interior of the body portion l6. Body portion 16 has a plurality of electrical terminals 24 embedded therein and extending from the interior region to the exterior region thereof. A shuttle member 26 is mounted within body portion 16 for bodily shiftable movement along and rotary movement about an axis of the housing member Typically, the shuttle member includes conductor means, not shown, operable upon bodily shiftable movement of the shuttle member to electrically connect selected ones of the terminals 24 to thereby energize the electrical circuits operative for exterior vehicle illumination. The shuttle member 26 is further adapted in a conventional manner, not shown, to control the level of instrument panel illumination such that rotary movement of the shuttle member through approximately 360 brings the instrument panel from a condition of full illumination to a condition ofzero illumination.

A control shaft arrangement generally designated 28 includes a shaft member 30 of generally triangular cross section rotatably and slidably journaled in central bore 22. The shaft member 30 has a longitudinally extending relief 32 in one surface and a decorative knob 34 fixedly secured to one end thereof. The other end of the shaft member 30 is operably connected to the shuttle member 26 at 36 so that rotation of and bodily shiftable movement of the shaft member rotates and bodily shifts the shuttle member 26. The control shaft arrangement further includes a cantilever type spring 38 having a stepped portion 40 located generally centrally thereof and an enlarged offset portion 42 at one end thereof. The other end of the cantilever spring 38 is fixedly secured to the shaft member 30 adjacent one end of the relief 32 by conventional means, as by welding, so that the cantilever spring 38 is rotatable and bodily shiftable as a unit with the shaft member. The cantilever spring is self-biased in a counterclockwise direction, FIGS. I, 2 and 3, about the point of connection with the shaft member 30.

With particular reference now to FIGS. 1, 3 and 4, the remainder of the electrical switch assembly includes a generally circular decorative bezel or knob seat 44. A generally cylindrical retaining member projects through knob seat and an aperture 54 in the instrument panel 10 and is threadably received within counterbore 20 of the housing member 14. Tightening of retaining member 50 in the threaded counterbore 20 draws the knob seat 44 snugly against the control mounting portion 10 of the instrument panel as the retaining member seats within a recessed area of the knob seat. Simultaneously, tightening of the retaining member 50 draws neck portion 18 of the housing member 14 snugly against the opposite side of the control mounting portion 10 to thus mount the entire switch assembly thereon. A relatively hard collar member 56 of generally cylindrical shape is fixedly secured within retaining member 50 and slidably receives the shaft member 30 and cantilever spring 38 and, as best seen in FIG. 4, defines a flat end surface 58 around the cantilever spring and shaft member in a plane generally perpendicular to the axis of the housing member.

In description now of the operation of the switch assembly, with the switch assembly deactivated, FIG. I, the shaft member 30 assumes a first or inactive position wherein the attached shuttle member 26 lies remote from the terminals 24 and the attached decorative knob 34 rests generally upon seat 44. The cantilever spring 38, in the inactive position of the shaft member, assumes a retracted position wherein it is forced by the side of central bore 22 to repose in relief 32 of the shaft member with the enlarged offset end 42 captured between the decorative knob and the seat. To activate the switch assembly for exterior illumination of the vehicle, the knob 34 is manually grasped and moved leftwardly, bodily shifting the shaft member 30 to a second outermost active position, FIG. 2, wherein the attached shuttle member bridges the gap between a plurality of the terminals 24 to complete the circuits for exterior vehicle illumination, conventionally the concurrent energization of both the head lamps and the parking lamps of the vehicle. lt is, of course, understood that an intermediate active position may illuminate the parking lamps only.

As the shaft member is bodily shifted leftwardly, more of the cantilever spring 38 is exposed to the left of central bore 22 and the cantilever spring begins to deflect in a counterclockwise direction. The collar member 56, however, restrains this deflection and functions as a guide for the cantilever spring during bodily shiftable movement of the shaft member 30. As the shaft member approaches the outermost active position, the stepped portion 40 on the cantilever spring approaches the end surface 58 of the collar member and, upon reaching coplanar relationship therewith, is urged to drop or snap thereover, H6. 2, thus defining an extended position of the cantilever spring wherein the enlarged offset portion 42 thereof is spaced from the shaft member 30 and knob 34. With the cantilever spring thus in the extended position, rightward or reverse bodily shiftable movement of the shaft member from the active to the inactive position is significantly impeded by the hooking engagement or detenting between the stepped portion 40 and the end surface 58 of the collar member56.

In the preferred embodiment, the included angle between the stepped portion 40 and the portions of the cantilever spring adjacent thereto is made larger than 90 so that in the extended position of the cantilever spring the engagement between the end surface 58 and stepped portion 40 is essentially point contact between a corner of end surface 58 and the oblique stepped portion 40. Under such engagement, a normal motivating force applied to knob 34 in an effort to bodily shift shaft member 30 from the active to the inactive position, F IG. 2, is successfully resisted by stepped portion 40 on the edge of end surface 58.-An abnormally large force, however, tends to earn the stepped portion 40 away from the edge of end surface 58 until the out board end of the stepped portion is searched, whereupon camming of the cantilever spring off the collar member is complete and the shaft member is freely bodily shiftable to the inactive position. The camming force is significantly larger than the force normally required to deactivate the switch to insure that a conscious effort on the part of the operator is put forth to deactivate the switch rather than a light or medium inadvertent bump. The camming force, however, is small enough that in the event of an emergency such as a collision the shaft member could be bodily shifted to the inactive position by the force of a passenger's body making contact therewith. The shaft member, thus, in the active position thereof does not present a rigid projection hazard within the vehicle.

The shaft member 30 remains rotatable in the active or inactive positions thereof, as is required for variation of the level of instrument panel illumination. In the inactive position, the cantilever spring reposes within the relief 32 of the shaft member to avoid interference with the central bore 22 as the shaft member and cantilever spring rotate therein. ln the active position of the shaft member, stepped portion 40 engages end surface 58 of the collar member and as the shaft member and cantilever spring rotate through 360, the stepped portion 40 is caused to slide without interference around the end surface 58 without affecting the detenting engagement between the stepped portion and the collar member 56.

To normally return the shaft member from the active to the inactive position thereof, the enlarged offset end 42, spaced from the shaft member and knob, is manually grasped and drawn toward the knob 34, rotating the cantilever spring clockwise to the retracted position thereof, FIG. 3, and disengaging the stepped portion 40 from end surface 58 of the collar member. Thus disengaged, the shaft member is bodily shiftable to the inactive position in response to a motivating force of normal magnitude applied by the same hand used to grasp offset end 42. It will be apparent, then, that for the switch assembly to be deactivated by a motivating force of normal magnitude experienced heretofore, the operator must consciously grasp and manipulate the enlarged offset end of the cantilever spring, thus being required to perform a positive action in addition to having a hand in the general area of the headlamp switch, This additional positive action required of the operator to deactivate the switch makes inadvertent deactivation significantly more difficult.

Having thus described the invention what I claim is:

1. ln combination in an electrical switch assembly including a housing member having conductor means therein operable to control said switch assembly in at least one mode thereof, the improvement comprising a shaft member, means operably connecting one end of said shaft member to said conductor means, means mounting said shaft member on said housing member for movement between active and inactive positions, a cantilever spring having detent means thereon, means fixedly securing one end of said cantilever spring to said shaft member, said cantilever spring being movable as a unit with said shaft member and movable relative thereto between retracted and extended positions, said cantilever spring being self-biased toward said extended position, abutment means stationary relative to said housing member and engageable by said detent means in said extended position of said cantilever spring and upon movement of said shaft member to said active position thereof, said abutment means engaged by said detent means being operable to significantly impede return movement of said shaft member from said active to said inactive position, and selectively operable release means operable to rotate said cantilever spring from said extended to said retracted position, said detent means being disengaged from said abutment means in said retracted position of said cantilever spring so that return movement of said shaft member to said inactive position is unimpeded.

2. The improved electrical switch assembly as recited in claim I wherein a knob is fixedly secured to one end of said shaft member and said release means comprises a distal end of said cantilever spring spaced form said knob in said extended position of said cantilever spring, said distal end being manually shiftable toward said knob to rotate said cantilever spring from said extended to said retracted position.

3. in an automobile type headlamp switch assembly including a housing member having mounted therein a shuttle member rotatable about an axis of said housing member to control said switch assembly in one mode thereof and bodily shiftable along said axis to control said switch assembly in another mode thereof, the improvement comprising a shaft member having a control knob fixedly secured to one end thereof and a longitudinally extending relief thereon, means operably connecting one end of said shaft member to said shuttle member, means mounting said shaft member on said housing member for bodily shiftable movement along said axis of said housing member between inactive and active positions and for rotary movement about said axis, a cantilever spring having a stepped portion intermediate the ends thereof, means fixedly securing one end of said cantilever spring to said shaft member generally in said relief of the latter, said cantilever spring being bodily shiftable and rotatable as a unit with said shaft member and rotatable relative thereto between retracted and extended positions, said cantilever spring being selfbiased toward said extended position wherein a distal end thereof assumes a position spaced from said knob, a generally cylindrical collar member, and means mounting said collar member on said housing member in fixed relationship thereto and slidably receiving said shaft member and said cantilever spring, said stepped portion of said cantilever spring being en gageable with an end surface of said collar member in said extended position of said cantilever spring and upon bodily shiftable movement of said shaft member to said active position thereof to significantly impede return bodily shiftable movement of said shaft member to said inactive position, and said distal end of said cantilever spring spaced from said knob being manually shiftable toward the latter to rotate said cantilever spring from said extended to said retracted position to allow unimpeded return bodily shiftable movement of said shaft member from said active to said inactive position. 

1. In combination in an electrical switch assembly including a housing member having conductor means therein operable to control said switch assembly in at least one mode thereof, the improvement comprising a shaft member, means operably connecting one end of said shaft member to said conductor means, means mounting said shaft member on said housing member for movement between active and inactive positions, a cantilever spring having detent means thereon, means fixedly securing one end of said cantilever spring to said shaft member, said cantilever spring being movable as a unit with said shaft member and movable relative thereto between retracted and extended positions, said cantilever spring being self-biased toward said extended position, abutment means stationary relative to said housing member and engageable by said detent means in said extended position of said cantilever spring and upon movement of said shaft member to said active position thereof, said abutment means engaged by said detent means being operable to significantly impede return movement of said shaft member from said active to said inactive position, and selectively operable release means operable to rotate said cantilever spring from said extended to said retracted position, said detent means being disengaged from said abutment means in said retracted position of said cantilever spring so that return movement of said shaft member to said inactive position is unimpeded.
 2. The improved electrical switch assembly as recited in claim 1 wherein a knob is fixedly secured to one end of said shaft member and said release means comprises a distal end of said cantilever spring spaced form said knob in said extended position of said cantilever spring, said distal end being manually shiftable toward said knob to rotate said cantilever spring from said extended to said retracted position.
 3. In an automobile type headlamp switch assembly including a housing member having mounted therein a shuttle member rotatable about an axis of said housing member to control said switch assembly in one mode thereof and bodily shiftable along said axis to control said switch assembly in another mode thereof, the improvement comprising a shaft member having a control knob fixedly secured to one end thereof and a longitudinally extending relief thereon, means operably connecting one end of said shaft member to said shuttle member, means mounting said shaft member on said housing member for bodily shiftable movement along said axis of said housing member between inactive and active positions and for rotary movement about said axis, a cantilever spring having a stepped portion intermediate the ends thereof, means fixedly securing one end of said cantilever spring to said shaft member generally in said relief of the latter, said cantilever spring being bodily shiftable and rotatable as a unit with said shaft member and rotatable relative thereto between retracted and extended positions, said cantilever spring being self-biased toward said extended position wherein a distal end thereof assumes a position spaced from said knob, a generally cylindrical collar member, and means mounting said collar member on said housing member in fixed relationship thereto and slidably receiving said shaft member and said cantilever spring, said stepped portion of said cantilever spring being engageable with an end surface of said collar member in said extended position of said cantilever spring and upon bodily shiftable movement of said shaft member to said active position thereof to significantly impede return bodily shiftable movement of said shaft member to said inactive position, and said distal end of said cantilever spring spaced from said knob being manually shiftable toward the latter to rotate said cantilever spring from said extended to said retracted position to allow unimpeded return bodily shiftable movement of said shaft member from said active to said inactive position. 